Shunt barrier in pulse oximeter sensor

Abstract

A pulse oximeter sensor comprising an emitter and a detector disposed on a substrate layer with a thinned portion between the emitter and the detector. A partially transparent covering layer covers the substrate layer and comprises a corresponding thinned portion. The thinned portions attenuate light shunted via the substrate layer and the partially transparent covering layer from the emitter to the detector, and may be configured such that less than 10% of the light detectable by the detector is shunted light.

1. A sensor comprising:
 a substrate; 
 a light emitter mounted on the substrate; 
 a light detector mounted on the substrate; and 
 a covering layer over the light emitter and the light detector, the covering layer comprising a first window for the light emitter, a first colored portion surrounding the first window, a second window for the light detector, a second colored portion surrounding the second window, and a transparent portion other than the first window or the second window, wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 10% of light detectable by the light detector is shunted light. 
 
     
     
       2. The sensor of  claim 1 , wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 1% of light detectable by the light detector is shunted light. 
     
     
       3. The sensor of  claim 1 , wherein the first colored portion and the second colored portion are substantially opaque to selected wavelengths of light from the light emitter. 
     
     
       4. The sensor of  claim 1 , wherein the first colored portion and the second colored portion are substantially opaque to red light and to infrared light. 
     
     
       5. The sensor of  claim 1 , wherein the covering layer is transparent except for the first colored portion and the second colored portion. 
     
     
       6. The sensor of  claim 1 , wherein first window and the second window are transparent. 
     
     
       7. The sensor of  claim 1 , wherein the first window and the second window have a color compatible with a calibration curve in the sensor for a wavelength of light from the light emitter. 
     
     
       8. The sensor of  claim 1 , wherein the first window and the second window extend at least 2 millimeters beyond the borders of the light emitter and the light detector, respectively. 
     
     
       9. The sensor of  claim 1 , wherein the first window and the second window extend at least 5 millimeters beyond the borders of the light emitter and the light detector, respectively. 
     
     
       10. The sensor of  claim 1 , comprising a sheath comprising a first layer and the covering layer, the covering layer coupled to the first layer so as to form a pocket, wherein the substrate is inserted into the pocket. 
     
     
       11. The sensor of  claim 1 , wherein the covering layer comprises a white portion between the first colored portion and the second colored portion. 
     
     
       12. A sensor substrate comprising:
 a base layer, wherein one end of the base layer comprises a location for a light emitter, and another end of the base layer comprises a location for a light detector; and 
 a sheath comprising a first layer and a second layer, the second layer coupled to the first layer so as to form a pocket for insertion of the base layer, wherein the second layer comprises a first window for the light emitter, a first colored portion surrounding the first window, a second window for the light detector, a second colored portion surrounding the second window, and a transparent portion other than the first window or the second window, wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 10% of light detectable by the light detector is shunted light. 
 
     
     
       13. The sensor substrate of  claim 12 , wherein the first colored portion and the second colored portion are substantially opaque to selected wavelengths of light from the light emitter. 
     
     
       14. The sensor substrate of  claim 12 , wherein the first colored portion and the second colored portion are substantially opaque to red light and to infrared light. 
     
     
       15. The sensor substrate of  claim 12 , wherein first window and the second window are transparent. 
     
     
       16. The sensor substrate of  claim 12 , wherein the second layer comprises a white portion between the first colored portion and the second colored portion. 
     
     
       17. A method of manufacturing a sensor comprising:
 providing a light detector mounted on a substrate and a light emitter mounted on the substrate; and 
 providing a sheath comprising a first layer and a second layer, the second layer coupled to the first layer so as to form a pocket for insertion of a base layer, wherein the second layer comprises a first window for the light emitter, a first colored portion surrounding the first window, a second window for the light detector, a second colored portion surrounding the second window, and a transparent portion other than the first window or the second window, wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 10% of light detectable by the light detector is shunted light. 
 
     
     
       18. The method of  claim 17 , wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 1% of light detectable by the light detector is shunted light. 
     
     
       19. The method of  claim 17 , wherein the first colored portion and the second colored portion are substantially opaque to red light and to infrared light. 
     
     
       20. The method of  claim 17 , wherein first window and the second window are transparent. 
     
     
       21. The method of  claim 17 , wherein the first window and the second window extend at least 2 millimeters beyond the borders of the light emitter and the light detector, respectively. 
     
     
       22. The method of  claim 17 , wherein the second layer comprises a white portion between the first colored portion and the second colored portion. 
     
     
       23. A method of remanufacturing a sensor comprising:
 providing a sensor comprising a substrate, a light emitter mounted on the substrate and a light detector mounted on the substrate; and 
 coupling a layer to the sensor over the light emitter and the light detector, wherein the layer comprises a first window for the light emitter, a first colored portion surrounding the first window, a second window for the light detector, a second colored portion surrounding the second window, and a transparent portion other than the first window or the second window, wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 10% of light detectable by the light detector is shunted light. 
 
     
     
       24. The method of  claim 23 , wherein the first colored portion and the second colored portion are configured to attenuate light shunted from the light emitter to the light detector such that less than 1% of light detectable by the light detector is shunted light. 
     
     
       25. The method of  claim 23 , wherein the layer comprises a white portion between the first colored portion and the second colored portion. 
     
     
       26. A method of operating a sensor comprising:
 emitting light at a patient with a light emitter mounted on a substrate, wherein the substrate is inserted into a pocket of a sheath comprising a first layer and a second layer, wherein the second layer is coupled to the first layer to form the pocket, wherein the second layer comprises a first window for the light emitter and a first colored portion surrounding the first window; and 
 detecting light from the patient with a light detector mounted on the substrate, wherein the second layer comprises a second window for the light detector, a second colored portion surrounding the second window, and a transparent portion other than the first window or the second window, wherein the first colored portion and the second colored portion attenuate light shunted from the light emitter to the light detector, wherein the first colored portion and the second colored portion attenuate light shunted from the light emitter to the light detector such that less than 10% of the light detected by the detector is shunted light. 
 
     
     
       27. The method of  claim 26 , wherein the first colored portion and the second colored portion attenuate light shunted from the light emitter to the light detector such that less than 1% of the light detected by the detector is shunted light. 
     
     
       28. The method of  claim 26 , wherein the first colored portion and the second colored portion are substantially opaque to red light and to infrared light. 
     
     
       29. The method of  claim 26 , wherein first window and the second window are transparent. 
     
     
       30. The method of  claim 26 , wherein the first window and the second window extend at least 2 millimeters beyond the borders of the light emitter and the light detector, respectively. 
     
     
       31. The method of  claim 30 , wherein the second layer comprises a white portion between the first colored portion and the second colored portion.